/*
*/
#include<stdio.h>
#include<conio.h>
#include <math.h>
int main()
{
int numGrades; //num of grades
int grade; //number grade
int sum=0; //sum of grades
float average; //average of grades
char letterGrade; //letter grade
int i; //loop variable
printf("This program calculates the average of as many grades you wish to enter.\n\n");
printf("First, enter the number of grades to process: ");
scanf("%d",&numGrades);
printf("\n\nNow enter the %d grades to be averaged.\n\n",numGrades);
for(i=0;i<numGrades;i++)
{
do
{
printf("Enter grade #%d: ",i+1);
scanf("%d",&grade);
if(grade<0 || grade>100) //validate grades
printf("*** Invalid entry. Grade must be 0 to 100. ***\n");
}while(grade<0 || grade>100);
sum=sum+grade; //add grades
}
average=sum/numGrades; //calculate average of grades
printf("The average of the %d grades entered is %.0f",numGrades, floor(average + 0.5));
//calculate letter grade
if(average>90 && average<=100)
letterGrade='A';
else if(average>80 && average<=90)
letterGrade='B';
else if(average>70 && average<=80)
letterGrade='C';
else if(average>60 && average<=70)
letterGrade='D';
else if(average<=60)
letterGrade='F';
printf ("\nYou have a letter grade of %c\n",letterGrade);
getch();
return 0;
}